A major goal of health disparities research is to identify mechanisms by which these disparities occur. Such research involves using measures of health and healthcare and of psychosocial, socioeconomic, occupational, and environmental factors. To conduct large studies that include multiple racial, the challenge for U.S. researchers is to understand how well measures developed in mainstream, well-educated samples are conceptually and psychometrically adequate when applied in these diverse U.S. population segments. Indeed, there is considerable evidence that many measures do not have comparable measurement properties across groups. We propose a workshop to advance the field of measurement in health disparities and cross-cultural research. The workshop was developed and will be chaired by the six measurement cores from the NIA-and NINR-sponsored Resource Centers for Minority Aging Research. A small group (12-14) of invited leading quantitative and qualitative measurement specialists and cross cultural researchers will convene in San Francisco for 1.5 days in May, 2001 to articulate the conceptual and measurement issues and to develop an agenda for this field of research. The invited experts and the RCMAR measurement core investigators will discuss: 1) how to raise awareness of the importance of such measurement studies, 2) priority areas and concepts for future measurement studies, 3) state-of-the-art qualitative and quantitative measurement methods to test the conceptual and psychometric adequacy of measures, and 4) ways to proceed in light on practical issues and constraints. Recommendations will be made as to how to proceed to assure consensus on the most critical issues to be discussed. The discussion and recommendations of the group will be published in Medical Care. Because this field of examining measurement equivalence in studies of health disparities in the U.S. is relatively new, having a group of experts discuss the issues and methods at this time, and prov ide guidelines and recommendations, can enable systematic approaches as health disparities research evolves.